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We establish the formalism of nuclear spin-isospin excitations,especially the Gamow-Teller resonance in a fully consstent relativistic random-phase approximation.A relativistic form of the Landau-Migdal parameter g‘ is adopted as a residual spin-isospin correlation force.In the non-relativistic limit it reproduces the excitation energy of the giant Gamow-Teller resonance state obtained in the non-relativistic model.The Gamow-Teller resonance for finite nuclei is investigated in a relativistic approach for the first time.It is found that the Ikeda sum rule of 90Zr is quenched about 8% in the Hartree as well as the correlated strengths due to the poles of the negative Dirac states at energies above 1 GeV. 相似文献
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测量了27,28P和相应同中子异位素在28Si靶上的中能反应截面.测得N=12和13同中子异位素的反应截面在Z=15处突然增大.对Z≤14同中子异位素和28P的实验数据结果可以用改进的光学极限近似的Glauber理论很好地描述.28P的反应截面能够用扩大核芯以改进的Glauber理论来解释.但是,用改进光学极限和少体近似的Glauber理论却低估了27P的实验数据.理论分析表明,扩大的核芯加质子晕可能是响应27P+28Si反应截面增强的机制. The reaction cross sections of~(27,28)P and the corresponding isotones on Si target were measured at intermediate energies. The measured reaction cross sections of the N=12 and 13 isotones show an abrupt increase at Z=15. The experimental results for the isotones with Z≤14 and~(28)P can be described well by the modified Glauber theory of the optical limit approach. The enhancement of the reaction cross section for~(28)P could be explained by the modified Glauber theory with an enlarged core. Theoretical ana... 相似文献
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本文用相对论Brueckner-Bethe-Goldstone(RBBG)方程研究核子-核的相对论微观学学势.核子的复有效质量是通过入射能量为200MeV的质子-40Ca散射数据来确定,由此进一步研究了质子对不同靶核:16O,40Ca,90Zr,208Pb能量范围从160—800MeV的相对论微观光学位.我们用这种微观光学位研究入射能量为200MeV质子与40Ca的弹性散射,并与唯象相对论光学位计算得到的截面,自旋可观测量进行了比较. 相似文献
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采用相对论平均场模型,计算了12C和40Ca的准弹性电子散射的字称不守恒不对称性A.研究了核内奇异夸克成份对A的影响. 相似文献
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A New Decomposition Approach of Dirac Brueckner Hartree—Fock G Matrix for Asymmetric Nuclear Matter
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Asymmetric nuclear matter is investigated by the Dirac Brueckner Hartree-Fock (DBHF) approach with a new decomposition of the Dirac structure of nucleon self-energy from the G matrix.It is found that the isospin dependence of the scalar and vector potentials is relatively weak,although boty potentials for neutron (proton) become deep (shallow) in the neutron-rich nuclear matter.The results in asymmetric nuclear matter are rather different from those obtained by a simple method,where the nucleon self-energy is deduced from the single-particle energy.The nuclear binding energy as a function of the asymmetry parameter fulfils the empirical parabolic law up to very extreme isospin asymmetric nuclear matter in the DBHF approach.The behaviour of the density depandence of the asymmetry energy is different from that obtained by non-relativistic approaches,although both give similar asymmetry energy at the nuclear saturation density. 相似文献
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应用Dirac Brückner-Hartree-Fock方法, 采用新的G矩阵分解方式研究了核子在核介质中的同位旋相关的相对论微观光学势,采用定域密度近似得到有限核的相对论微观光学 势.讨论了有限核的相对论微观光学势及其Schrdinger等价势与入射质子能量的关系,计 算了200MeV以下质子入射4040Ca和208208Pb核的弹性散射角分布 和分析本领,得到了与实验相一致的结果,并将这种方法推广用于不稳定核的研究.通过对C a同位素的计算可以看出,在相
关键词:
相对论微观光学势
Dirac Brückner-Hartree-Fock
不对称核物质
定域密度近似 相似文献
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Radioactive decay of super heavy nuclei via the emission of α-particles has been studied theoretically in the preformed cluster model (PCM). The nucleus-nucleus (NN) potential is obtained by double folding the density distributions of the α-particle and the daughter nucleus with a realistic effective interaction. The M3Y effective interaction, supplemented by a zero-range pseudo-potential for exchange term, is used to calculate the NN potential. The α decay half-lives for 317 nuclei at Z=102 120 are performed in the PCM framework with the theoretical Q values extracted from the MSller-Nix-Kratz and Liran-Marinov-Zeldes mass tables and are compared with the experimental data. The calculated results are also compared with those obtained by using Q values from the Muntian-Hofmann-Patyk-Sobiczewski and Myers-Swiatecki mass estimates. 相似文献